In which type of cancer are the urinary excretion of the breakdown products of catecholamines, especially vanillylmandelic acid (VMA) and homovanillic acid (HVA), detected?
Correct Answer: A
Rationale: The correct answer is A: Neuroblastoma. Neuroblastoma, a cancer that arises from nerve tissue, is associated with increased levels of catecholamine metabolites, including VMA and HVA, in the urine. Nephroblastoma (Wilms tumor) is a type of kidney cancer and is not typically associated with elevated levels of catecholamine breakdown products. Leukemia is a cancer of the blood and bone marrow and does not lead to increased VMA and HVA excretion in urine. Osteosarcoma is a bone cancer and is not linked to elevated levels of catecholamine metabolites in the urine.